Model "DA2" Differential Pressure Reducing Regulator (Series II)-PDRV; Body Size 1/2",Opt-81: Full Diaphragm Support Construction; Sales Kit A; Cf3m Body,316l SST Spring Chamber,1/8" SST Petcock Vent; P Trim: 17-4ph SST Trim With Polyall Seat,Ethylene Propylene(Epr);Diaphragm; Ethylene Propylene(Epr) Static Seals,Tfe U-Cup W/SST Energizer Dynamic;Seal;